The invention relates to apparatus for manipulating sheets, particularly printed sheets such as front page or main sections or inserts of newspapers, signatures and the like. Still more particularly, the invention relates to improvements in sheet transporting apparatus of the type wherein a first conveyor advances a series of sheets along a first path, a second conveyor serves to advance the sheets of the series along a second path, and a third conveyor serves to transfer successive sheets of the series from the first conveyor to the second conveyor.
Commonly owned copending patent application Ser. No. 07/317,737 and now U.S. Pat. No. 5,050,851 discloses an apparatus wherein a first conveyor advances a series of sheets in suspended position for deposition of successive sheets into receptacles (e.g., in the form of pockets) forming part of a second conveyor in an inserting machine. The first conveyor has grippers which support discrete sheets of the series in suspended position, and a third conveyor which serves to transfer sheets from successive grippers of the first conveyor into successive pockets of the second conveyor comprises or constitutes a ramp or chute along which the sheets slide on their way from a gripper into the registering pocket of the second conveyor.
A drawback of the just described apparatus is that it cannot rapidly transfer relatively thin and/or relatively large sheets with a required degree of reliability. The reason for such unreliability of the apparatus in connection with the transfer of relatively thin (readily flexible) and/or relatively large sheets is that the orientation of sheets relative to the respective grippers and/or relative to the ramp or chute is likely to change due to the resistance of air in the path of movement of rapidly advancing sheets. On the other hand, it is desirable to deliver successive sheets of a short or long series in suspended position because this facilitates their transfer into the receptacles of the second conveyor, e.g., into the aforementioned inserting machine for assembly of newspapers or the like.